A milkman wants to empty a large drum full of milk with one of the four measuring jars of capacities 6. 9, 15 and 18 litres, respectively. He finds that no matter which jar he uses to empty the drum; 4 litres of milk always remains to be emptied. What is the least possible capacity of the drum if it is a multiple of 7?

A

191 liters

B

187 liters

C

364 liters

D

94 liters